1. Field of the Invention
The invention relates generally to a liquid-crystal cell and more particularly to a liquid crystal cell wherein the liquid-crystal substance is contained between two cell plates coated on their inner side with electrodes, separated from each other by spacing elements and hermetically sealed by sealing material, the electrodes of the two cell plates being partly connected to each other by means of electrically conducting material, and a method for manufacturing such a liquid-crystal cell.
2. Description of the Prior Art
In a liquid-crystal cell intended to serve as a display device, the layer of liquid crystal is contained between two transparent cell plates provided with defined electrode structures. The design arrangement is usually of such a kind that the conducting parts on one of the two electrode surfaces are connected in groups or all together, and therefore, have only a few connections, there often being only one common electrical connection. The other, opposite electrode surface in the case of digital displays, for example, is divided into segments so that the segments of each numeral can be activated individually.
In order to facilitate the contact layout between display circuits and control circuits, it is desirable to have all the contacts in a single plane. An effective way of doing this is to lead the relatively few electrode connections of one electrode surface across to the other, highly segmented electrode surface. For this, the gap between the two electrode-coated cell plates, which corresponds to the thickness of the liquid-crystal layer, must be bridged electrically.
Various methods of creating electrical contact bridges of the kind described have already been proposed. Thus a method is known from German patent application DOS No. 2,058,104 published May 31, 1972 whereby metal wires (e.g. gold wire) are clamped between the electrodes at suitable points to serve both as electrical bridges and also as spacing elements. Another method is described in German patent application DOS No. 2,201,267 published July 26, 1973. Here, local inductive heating is employed to join a metal film to the similarly softened support plate. According to German patent application DT-OS No. 2,240,781 published Feb. 22, 1973, the necessary contact is achieved by joining together electrically some of the electrodes of the opposing plates outside the cell cavity containing the liquid-crystal substance.